Propeller.



F. C. GOETTERT.

PROPELLER.

APPLICATION FILED DEC-28, 1914.

1,198,21 1-. Patented Sept. 12, 1916.

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stantially parallel arrangement.

FRED C. GOETTEBT, 0F ABERDEEN, WASHINGTON.

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Specification of Letters Patent. Patented Sept. 12, 1916.

Application filed December 28, 1914. Serial No. 879,297.

To all whom it may concern: 1

Be it known that I, FRED C. Gon'r'rnn'r, a citizen of the United States,and a resident of Aberdeen, in the coimty of Ghehalis and State ofWashington, have made certain new and useful Improvements in Propellers,of which the following is a specification.

My invention is an improvement in propellers, and has for its object toprovide a device of the character specified, adapted for use in watercraft of every character, and wherein the propelling mechanism isarranged to bore into the water, instead of pounding against the water,thus reducing slippage and increasing the speed in accordance withpower, saving fuel, and reducing vibration of the boat and slippage ofthe propeller, and facilitating reversing, and eliminating swell anddead water.

In the drawings: Figure 1 is a perspective view of the propeller mountedon its shaft,

and Fig. 2 is a longitudinal section slightly enlarged.

The present embodiment of the invention is shown in connection with apropeller shaft- 1 having a key-way 2 at its lower end, for engagementby a key 3, which prevents the blade to be described from rotation withre-' spect to the shaft.

The propeller proper comprises a hub 4 adapted to fit the shaft closely,and blades 5 and 5' spirally arranged with respect to the hub and theshaft, and the blades are integral with the hub. Each blade it will benoticed from an inspection of Fig. 2 is of considerable thickness at thehub, gradually decreasing in thickness toward its free outer edge. Eachof the blades 5 and 5 extends half way around the hub, the two bladesbeing oppositely disposed and having a sub- The front and rear faces ofthe blades are straight 'at one end and convex and concave,respectively, at the opposite end as indicated most clearly in Fig. 2.The intermediate faces of the blades gradually conform to the terminalfaces. In practice the propeller is arranged with the ends of the bladeshaving the straight faces forward and the ends with the concavo-convexfaces rearward. Thisgives the best results as the blades obtain amaximum working purchase upon the water and a minimum work detractingresistance.

The key 3 prevents rotary movement of the hub and shaft with respect toeach-other, and the hub is provided with a key-way 6 registering withthekey-way 2 for receiving the key. A pin 7 is passed transversely ofthe shaft at the lower end of the hub, to prevent displacement of thepropeller longitudinally oftheshaft. The pitch of the blades 1s inaccordance with conditions, and the size will depend upon the size ofthe boat with which the propeller is to be used.

The improved propeller is non-breakable when in motion, and should ablade strike an obstruction, it will easily slip off of the same withoutbecoming caught and broken. The direction of movement of the boat isquickly changed with the improved propeller, and the reverse is almostinstantaneous with practically no swell and no dead water. The vibrationof the body is greatly reduced, and there is also a great saving in fuelamounting from thirty-three and one-third to-forty per cent. Theimproved wheel bores into the water, instead of pounding, thus reducingvibration and slippage to a minimum.

The blades may be made much stronger,

, because they extend so shorta distance from the axis of rotation, andby making them of greater thickness adjacent to the hub, they arestrengthened and reinforced at this point. With the ordinary form ofpropeller, when rotated beyond apredetermined speed, power is lost, thewater being driven away from the propeller, so that there is nothingforithe propeller to push against. With the present form this cannothappen.

I claim:

1. A screw propeller embodying oppositely disposed spirally arrangedblades, said blades having their front and rear faces straight at oneend and convex and concave, respectively, at the opposite end, andhaving the intermediate faces gradually conforming to the terminalfaces.

v2. A propeller comprising a hub, oppositely disposed blades extendinghalf Way the intermediate faces gradually conform.- around the hub in aspiral direction, said ing to the terminal faces. blades being thickadjacent to the hub and tapering toward their outer edges, said FREDGOE'TTERT' blades having their front and rear faces WVitnesses:

straightat one endiand convex and concave, H; M: Le- RUE JIL,

respectively, at the opposite end; and having DJ J: COLLINS.

Copies of this patent may--be-obtainedfor five: centseach, byaddi'essingzthe Commissioner of Patents, Washington, I). G.

